Page:Popular Science Monthly Volume 60.djvu/179

Rh of matter; the doctrine of films, which recalls Newton's corpuscular theory and the very recent discovery of the 'Becquerel rays'; the relations of waste and repair in youth and age; the inviolability of natural law.

Of special interest to us is a passage in the fifth book which sets forth the ideas of the struggle for existence and natural selection in terms of remarkable clearness for a pre-Darwinian writer. Lucretius even announces them in connection with the domestication of animals, which was the precise point from which Darwin started in his effort to account for 'the origin of species.'

And many races of living things must have then died out and been unable to beget and continue their breed. For in the case of all things which you see breathing the breath of life, either craft or courage or else speed from the beginning of its existence protected and preserved each particular race. And there are many things which, recommended to us by their useful services, continue to exist consigned to our protection. In the first place, the fierce breed of lions and the savage races their courage has protected, foxes their craft and stags their proneness to flight. But light-sleeping dogs with faithful heart in breast and every kind which is born of the seed of beasts of burden and at the same time the woolly flocks and the horned herds are all consigned, Memmius, to the protection of man. For they have ever fled with eagerness from wild beasts and have ensued peace and plenty of food obtained without their own labor, as we give it in requital of their useful services. But those to whom nature has granted none of these qualities, so that they could neither live by their own means nor perform for us any useful service in return for which we should suffer their kind to feed and be safe under our protection, those, you are to know, would lie exposed as a prey and booty of others, hampered all in their own death-bringing shackles, until nature brought that kind to utter destruction.

In close sequence comes the most interesting portion of the entire poem, the detailed account of the evolution of human society from the rude 'life after the roving fashion of wild beasts' up to the settled security and elegancies of the highest civilization. Noteworthy in this account is the representation of childhood as the first humanizing influence, the origin and growth of language, religious beliefs and social order, the development of industries and of art, until the poet himself appears 'to consign the deeds of men to verse.' Thus, says Lucretius, "time by degrees brings each several thing forth before men's eyes, and reason raises it up into the borders of light; for things must be brought to light one after the other and in due order in the different arts, until these have reached their highest point of development."